Former FARC guerrilla Diomedes holds the baby of a visiting relative of a fellow rebel of the Revolutionary Armed Forces of Colombia, FARC, in the Yari Plains, southern Colombia, Sunday, Sept. 25, 2016. President Juan Manuel Santos and FARC leader Rodrigo Londono, alias Timochenko, are expected to sign a peace accord to end more than five decades of conflict Sept. 26 in the Caribbean city of Cartagena. (AP Photo/)

Colombia is to take another key step toward peace on Monday, as President Juan Manuel Santos and leader of the Revolutionary Armed Forces of Colombia (FARC), Rodrigo Londoño Echeverri aka Timochenko, sign a peace deal.

The ceremony, taking place in the country’s coastal city of Cartagena, is scheduled to be witnessed by up to 15 Latin American presidents, with UN Secretary-General Ban Ki-moon and US Secretary of State John Kerry also scheduled to attend. It brings the country to the cusp of a peace that will end half a century of conflict, responsible for the death of a quarter of a million people, described by President Santos as ‘the oldest, the cruelest’ conflict in the Western hemisphere.

“War is always more costly than peace,” Santos told the BBC. “A country at war for 50 years is a country that has destroyed many of its values.”

There is now real hope that peace can endure between the Colombian authorities and the country’s biggest rebel group, allowing a reclamation of those values, as well as a boost to the nation’s – and its people’s – prosperity.

Hurdles and concerns remain, not least a plebiscite on Oct. 2, in which the country’s people must vote on whether to accept the deal. Many harbor reservations that the terms are too lenient for the rebels, replacing jail time with development work for those who confess to their abuses.

Yet polls indicate that the accord will pass the people’s judgement. Moreover, in spite of the shortcomings highlighted by critics, the process has earned praise as a groundbreaking approach to conflict resolution, particularly with regard to its involvement of victims.

Even if this peace agreement is implemented, however, other threats to the country’s security remain. Talks between the government and a smaller rebel group, the National Liberation Army, have stalled of late, though a successful conclusion to the FARC’s negotiations could reinvigorate that process.

A bigger obstacle for the government, perhaps, is the multitude of criminal enterprises managed by the FARC, including its domination of the illicit drug trade. When its fighters lay down their arms and enter the rehabilitation process outlined in the agreement, they may leave a vacuum that others will eagerly seek to fill.

“Colombia’s conflict has a multitude of actors, and the FARC is just one,” wrote Elizabeth Dickinson in Foreign Policy. “Even if the guerrillas disband quickly and quietly, their illicit economy – and the bloodshed it generates – is too lucrative and tempting to disappear anytime soon.”

Yet whatever challenges may lie ahead, there can be little doubt that peace between the government and the FARC will represent an enormous boon for Colombia. In honor of that fact, the ceremony taking place in Cartagena will be steeped in symbolism, the 2,500 guests invited to wear white as an ode to peace, and the president signing the deal with a pen made from the casing of a shell used in combat.

“The signature of the deal is simply the end of the conflict,” Santos told the BBC. “Then the hard work starts: reconstructing our country.”

Material from the Associated Press and Reuters was used in this report.